Comparison of the N-terminal portion of the Arabidopsis GDP-mannose pyrophosphorylase with the analogous portion of the enzyme from other organisms. The following are the GenBank accession numbers for the GDP-mannose pyrophosphorylase sequences aligned with the Arabidopsis pyrophosphorylase: Saccharomyces cerevisiae, 1431053; Synechocystis sp., 1653346; Acetobacter xylinus, 2569943; Aquifex aeolicus, 2983302; Escherichia coli, 3142209; Vibrio cholerae, 1230580; Salmonella typhimurium, 117277; Yersinia enterocolitica, 1197654; Xanthomonas campestris, 267418; and Mycobacterium tuberculosis, 1877319. Note that the porcine (Sus scrofa domestica, 476970) sequence is from N-terminal sequence data obtained from the B chain of GDP-mannose pyrophosphorylase. The proline highlighted in boldface (P) is the wt amino acid converted to a serine (→S) in vtc1-1 and vtc1-2.